The perfume industry is in constant need of new perfume ingredients, capable of enlarging and/or improving the palette of odor notes already available to the perfumer. The compounds of formula (I) defined above bring a new contribution to this field.
We have now discovered that compounds (I), which are novel chemical compositions, possess very useful odor properties and can therefore be used for the preparation of perfuming compositions and perfumed articles. They are, in fact, capable of developing odor notes of the musky, ambrette type, together with fruity, and sometimes floral, type characters.
The compounds according to the invention may present themselves in a pure state or in the form of a mixture of isomers, and this as a function of the nature of substituents R.sup.1 to R.sup.4. Thus, compounds (I) may present themselves in the form of a mixture of isomers of formula (Ia) and (Ib) as defined above, or as a mixture of isomers of formula (Ic) and (Id) as defined above. Said mixtures are also an object of the present invention. We have, in fact, observed that these mixtures were also advantageous perfuming ingredients which could be used as alternatives to their individual ingredients.
Amongst the compounds of formula (Ia) to (Id), the compounds of formula (Ib) or (Id) are cited as preferred compounds according to the invention, their odor possessing a more pronounced musk-ambrette character, neater and more elegant, than that of compounds (Ia) or, respectively (Ic).
In addition, it has also been observed that, in spite of their common musk-ambrette character, optically active isomers of the preferred compounds (Ib) or (Id) also possessed distinct odor properties and that some isomers could perform better than others.
Amongst the compounds of the invention, 4-(3,3-dimethyl-1-cyclohexyl)-2,2-dimethyl-3-oxapentyl propanoate is cited as a preferred compound. It develops a musky, ambrette odor, possessing a floral undernote and a fruity character of the pear type. This combination of ambrette and pear characters is particularly useful and quite typical of the series of compounds (I), which impart to the compositions into which they are incorporated wholy unexpected odor notes of the pear and ambrette seeds type, as is apparent from the application examples presented further on.
The fragrance effect imparted by the above-cited preferred compound of the invention is even more powerful and muskier when said compound is used in the form of one of its optically active isomers, i.e., the compound of formula ##STR7## or (+)-(1'R,4S)-4-(3',3'-dimethyl-1'-cyclohexyl)-2,2-dimethyl-3-oxapentyl propanoate. However, the other optically active isomers of this compound are also very useful perfuming ingredients. Likewise, the mixtures of 4-(3,3-dimethyl-1-cyclohexyl)-2,2-dimethyl-3-oxapentyl propanoate with 4-(3,3-dimethyl-1-cyclohexyl)-1,1-dimethyl-3-oxapentyl propanoate also proved to be perfuming ingredients of useful application according to the invention, having the advantage of being less costly than the preferred pure compound cited above.
Other preferred perfuming ingredients of the invention include 4-(3,3-dimethyl-1-cyclohexyl)-2-methyl-3-oxapentyl propanoate and 4-(3,3-dimethyl-1-cyclohexyl)-1-methyl-3-oxapentyl propanoate, as well as mixtures thereof. These compositions of matter developed odor notes of the musky, ambrette type, with a neat character of William pear. From an olfactive point of view, 4-(3,3-dimethyl-1-cyclohexyl)-2-methyl-3-oxapentyl propanoate is the more preferred isomer.
The odor properties of other compounds according to the invention shall be described in detail in the corresponding preparation examples presented further on.
The compounds and mixtures of the instant invention can be used with equal advantage in both fine perfumery, for the preparation of perfuming compositions and bases, and functional perfumery, for perfuming varied consumer articles. Examples of the latter include soaps, shower or bath gels, shampoos and other hair-care products, body or air deodorants. They are also useful for perfuming detergents or fabric softeners and household products.
In the above-mentioned applications, the compounds of the instant invention may be used alone or in admixture with other perfuming co-ingredients, as well as with solvents or carriers of current use in perfumery. The concentrations in which they are used can vary in a wide range of values. The man in the art knows by experience that such values are a function of the desired perfuming effect, as well as being dependent on the nature of the other co-ingredients in a given composition. By way of example, one can cite values of the order of 5 to 10%, or even 20% or more, by weight, of the compound or mixture according to the invention, relative to the weight of the composition. These values can be much lower when the compounds of the invention are used for perfuming the above-cited functional articles.
The compounds of formula (I) or their mixtures according to the invention are prepared by an original process comprising the treatment, with an appropriate esterification agent, of an hydroxy-ether of formula ##STR8## wherein symbols R and R.sup.1 to R.sup.4 have the meaning indicated in formula (I), or of a mixture of structural isomers of formula (II).
The hydroxy-ethers of formula (II) used as starting products in the process of the invention can be prepared from the appropriate ethanones as schematically represented hereinafter. In this scheme, symbols R and R.sup.1 to R.sup.4 have the meaning indicated in formula (I).